My Bora's first trip to the doctor

[Coralon]

I believe the 8L A3/S3 diff will also fit as it is the same chassis, haldex etc. If you are looking to source overseas then you also have the option of any mkIV 4motion golf.

[djorkboy]

So the latest in my saga...

I have yet to hear back from my mechanic on what the cost for diff reconditioning will be. He says the place he sends diffs to for reconditioning is busy and should be able to get me some info by Tuesday or Wednesday this week.

I have located a second hand diff for sale, it is from a low mileage (25k, not sure if that is miles or kms) V6 Golf 4motion from the UK. The diff was imported to Australia and the current owner says it has been stored for 8 years.

So if a diff sits for 8 years unused (filled with fluid) will it deteriorate? It looks to be in good condition externally.

[grtuned]

Is it still filled with oil?? if so and if it has not been rotated there's a chance half of crown wheel might be rusty. You would have to flip it let it sit then rotate it and see how backlash feel's, Also seals will need to be checked, As for Haldex condition who knows???
Either way your taking a risk no matter how you purchase unless you get it from sydney and have the option to take it back.
Tough call!!!!

[djorkboy]

well, the slow trickle of news about my diff continues.

The culprit is definitely hardened bearings in the diff, which is really relatively good news, it means there has been no catastrophic failure of more expensive diff parts. At this point the diff guy is still picking through to make sure there is no damage on the other parts of the diff, he did mention there is a 'harshness' of some sort somewhere else in the diff and he is hunting around to find the cause of it.

So I should know by Monday what the final cost will be and when I can have my car back.

I have been careful not to push my mechanic too hard on this as he is trying to be as thorough as possible and only replace the parts the really need to be replaced while at the same time making sure the diff is fixed properly the first time. It really helps to have a mechanic you can trust.

[djorkboy]

Finally got the full results. The diff recondition is going to cost me $2300, which is definitely a lot of money but it could have been so much worse so I am pretty happy.

All the internal bearings in the diff were trashed, everyone involved agrees that the reason for this is the bizarre VW policy that Bora 4motion rear diffs are a no-maintainance part and never need the fluid changed.

I will have my Bora back by Friday and I'm very excited.

Even with the $2300 expenditure after less than 2 months of owning the car it has still cost me less than any Bora 4motion on sale today in the country.

[Coralon]

Good to hear you got to the bottom of it and the cost isnt so bad but still a lot.

A quick google search turned up this thread which leads me to believe that after reading your story and this old one that maybe a 163~km I should propbably look at my diff oil before it too starts to whine or worse.

So much for lifetime use... or maybe lifetime is a predetermined number of years and does not take into account people will still be driving these cars 8-15 years later.

edit: And after reading this little gem I will be taking a serious look at all the 'lifetime' stuff.

[Cookie28]

I was having a look in my service manual the other day and it said that the diff oil was changed every 60k or 90k I'm pretty sure

[djorkboy]

I was having a look in my service manual the other day and it said that the diff oil was changed every 60k or 90k I'm pretty sure

Are you sure you aren't talking about the Haldex? I think mine says the Haldex viscous coupling unit needs a fluid and filter change every 60,000k but it says nothing about the diff.

About 2 weeks ago my mechanic called VW to ask them what the servicing schedule for a MkIV 4motion rear diff is and he was told that it is a 'lifetime' part and never needs a fluid change or any servicing.

[Coralon]

Just looked at the 4mo service manual and the only thing in there that even relates to a diff (but its not) is the automatic gearbox final drive oil change every 90k and as the 4mo never came with an auto... you guessed it, this is not relevent. Haldex is definately every 60k but diff is never mentioned.

After some more investigating 'lifetime' really is a legal term relating to manufacturer warranty periods to reduce total cost of ownership from new until you flog it off because you no longer have a warranty. Change your fluids lads, its malarky

[djorkboy]

Finally the day has come, I picked up the Bora this afternoon. Very happy with the results, car is smooth and quiet with no grumbling or whining from the rear.

End cost was $2077 including new bearings, diff recondition and a Haldex fluid and filter change so I'm actually pretty happy with the outcome financially.

As Coralon said, change your fluids, even the ones VW don't tell you to change.